Dial Bore Gauge Kit, 50–160mm Range, Cylinder Bore Gauge Indicator for Piston Engine Wear, Taper, and Out-of-Round Measurement
Estimating cylinder wear by feel or visual inspection is not a measurement — it is a guess, and on an aircraft piston engine it is a guess that will show up at the next overhaul or, worse, in service. Supplied by JHEARs Aerospace, this dial bore gauge kit measures cylinder bore wear, taper, and out-of-round conditions to a resolution sufficient to catch the deviation that determines whether a cylinder is still within serviceable limits or requires action before the engine goes back into service. The 50 to 160mm measurement range with interchangeable pins covers the cylinder bore sizes encountered across most piston aircraft engines, making it a single instrument solution for the bore measurement task rather than requiring multiple gauges for different engine types.
The self-centering design ensures the gauge contacts the bore at the correct measurement point without relying on the operator to manually find the centreline, and the carbide-tipped anvils are built to maintain their dimensional accuracy through repeated use across years of shop work rather than wearing and drifting over time. The insulated grip keeps the instrument comfortable and thermally stable during use, and the moulded carry case protects the instrument between jobs rather than leaving a precision measurement tool exposed in a drawer where it will be damaged and knocked out of calibration.
Spec: Dial bore gauge kit, measurement range 50–160mm. Interchangeable pin set for range coverage. Self-centering design. Carbide-tipped anvils. Resolution to 0.001mm. Insulated grip. Moulded carry case. Suitable for cylinder bore wear, taper, and out-of-round measurement on piston aircraft engines and engineering applications.
Who this is for: Aircraft mechanics and A and P technicians performing piston engine cylinder inspection and overhaul measurements, engine shops measuring bore condition during top overhaul and major inspection work, and engineering professionals requiring a precise, durable dial bore gauge for cylinder and bore measurement tasks across a range of engine and mechanical applications.
FAQ
What cylinder bore sizes does this kit cover with the included interchangeable pins?
The kit covers a measurement range of 50 to 160mm using the included set of interchangeable extension pins. This range encompasses the cylinder bore diameters found across most common piston aircraft engines used in general aviation. Verify your specific engine's bore diameter against the kit range before purchase to confirm suitability.
How do I use a dial bore gauge to check for cylinder taper and out-of-round?
Take measurements at multiple positions along the cylinder bore axis to check for taper, comparing top, middle, and bottom readings. Take measurements at multiple rotational positions at each axial location to check for out-of-round. Compare all readings against the serviceable limit specifications in your engine overhaul manual to determine cylinder condition.
How often should the bore gauge be calibrated and how is it set to zero?
The gauge should be zeroed before each measurement session using a calibration ring gauge or precision setting ring of a known diameter, or against a micrometer set to the nominal bore size being measured. Regular calibration checks against a known reference ensure measurement accuracy is maintained over the life of the instrument.
Why should I purchase my engine measurement instruments from JHEARs Aerospace?
At JHEARs Aerospace, we supply precision measurement instruments selected for professional use in aviation engine maintenance and overhaul environments. Our range is chosen to give mechanics and engine shops the measurement capability they need to make confident, documented serviceable limit decisions on the components they inspect.
